Electric lighting.



PATENTED JULY 9, 1907.

W. J. PHELPS.

ELECTRIC LIGHTING.

APPLIoATIoN FILED JULY 15, 190s.

narran srarns Parana ormoni.

WILLIAM J. PHELPS, OF DETROIT,\MIO'HIGAN.

ELECTRIC LIGHTING.

'Applicatiouiiled July 15,

To all whom it may concern: l

Be it known that I, WILLIAM J. PHELr's, a citizen of the United States, and a resident of Detroit,'county of vWayne, and State of Michigam'have invented certain new and useful Improvements `in Electric Lighting, of which the following is declared to be a full, clear, and exact description.

The improvement relates to electric incandescent lighting in which the lamps are provided with two or more filaments or sections and are designed to emit light of varyingV intensity. l

The invention Aconsists in the features of construction, combinations and arrangement of parts hereinafter set forth, illustrated inthe accompanying drawings and more particularly pointed out in the appendedv claims,

In the drawing: Figure l is a section through one of the lamps and vits holder and a diagram of the circuit and switch employed. Fig. 2 is an end view of the lamp. Fig. 3 is a cross-section of the lamp holder on line 3 3 of Fig. l. Fig. 4 is a section of a modified form of lamp and holder.

As shown in the drawing, the base or cap of the lamp preferably comprises a' screw shell 10, which forms one of the lamp terminals for the reception of current from the lamp holder and which supports within its outer end a glass globe or vacuum bulb. 11, held therein by suitablecomposition filling l2. An insulating disk l13 of porcelain or like material is mounted within the end of the screw shell 10 and carries a second and a `third terminal for the reception of current from the lamp holder. -One of these terminals comprises a metallic tubular rivet 14, extending through a central hole in the disk l3fand flanged outwardly at each end to hold the same in place. VThe third terminal is mounted upon the disk intermediate the'central terminal and the i edge thereof, and preferably comprises bent piece 15 of spring-metal which is held upon the ce of the disk by the outer flanged end of the tubular rivet or terminal 14, but, as shown, the terminal l5 is insulated from the terminal 14 by .a washer 16 of suitable material. The outer end of the resilient or axially yielding termi nal is formed in the shape of an annulus or loop concentrically arranged about the central terminal 14.

Lamp filament or filament sections 17 and 18 are employed, which are of different candle'powertand low power lament 18 is of greater resistance per unit of length than high power filament 17 Three leading-in `wires 19, 20 and 21 are connected respectively with the central terminal 14, the screw-shell terminal 10 and the` resilient terminal 1,5 of the lamp. The leading-in wires 'extend'within the neck of the lamp'and wire 19 is connected to the joined ends of the filaments, and the wires 20 and 21are connected respectively to the free ends of the high and low power filaments 17 and 18.

The lamps are designed for use with a current of conspecincation 'of Letters Patent.

Patented July 9, 1907. 1903.A Serial No. 165,556.y i

stant or fairly constant potential and when current. ows from terminal 15 to terminal 10 through the filaments in series, lowhpower filament 18 will alone glow with small candle power, while high power filament 17 acts as a dark and dead resistance because ofthe different relative resistance of the filaments. By short circuiting the low power filament, by connecting terminal 14 to one of main current supply wires, low power lament 18 will ble short circuited and the high power filament 17 'will alone glow with full candle power.

The holderfor the lamp comprises a' recessed block or receptacle 23 of porcelain or like material, having within its recess a metal screw-shell 24, which constitutes one of the holder terminals and within which the' screw-shell terminal 10l of the lamp is threaded. A metal strip 25 extendslaterally through an opening in the 'receptacle 23, is connectedto the screw-shell 24 and is provided on its outer endl with a binding screw '26. 'Another holderl terminal comprises a central stud 27, extending axially through the base of the receptacle 23 and adapted to engage the central terminal 14 of the lamp. The inner end of the stud or terminal 27 is provided with a shoulder 27', tting within a recess in the bottom of receptacle 23 and kprovided on its outer end with a binding nut 28. The third lamp terminalcoma prises a metal annulus or ring 29 concentricallymount- `ed upon the bottom of the receptacle 23 about the te'rminal 27. A metal strip 30 connected to or formed in piece with the annular terminal 29 extends laterally through an opening in the side of receptacle 23 and is provided o n its outer end with a binding screw 31. AThe i annular holder terminal 29 is adapted to be snugly engaged by the `annular resilient lamp terminal` 15. By this arrangement the lamp and holder are provided with three pairs of co-operating terminals for the transmissionvof current to thelamp filaments, and by making" one of such terminals resilient or 'axially yielding; l each terminal of the three pairs may make good contact' with its corresponding terminal.

In Fig. 4 is illustrated a slightly modiedform in which-lamp terminal 15 is a-flat annulus fixed to the end disk 13, and the corresponding holder terminals 29 is resilient or axially yielding and is formed of a bent strip of spring metal. i i I Three conductors 32,V 33 and 34 are connected respectivelyby binding lnut 28 and lbinding screws 26 and 31 to the three terminals 27, 24 and 29 of the lamp holder and extend therefrom to a distant conveniently located switch. l I

Main current supply wires 35 and 36 areconnected respectively to a binding post 37 and to'a switch 38. l 4The latter is adapted to successively engage a pair of contacts 39 and 40 to which conductorsl 32 and 34 are respectively connected. Conductor '-33 is connected to the binding post a7.

When switch 38 is in the position shown, the current is turned ofi from the lamp or lamps.' When shifted into engagement with contact 4l), the lcurrent passes the laments ofl'the lamp in series andthelower power filament 18 alonev glows as above described. `When switch 38 is shifted into engagemnet with contact .39, the low power filament is short'circuited andthe high power lament 17 will-alone glow. `4

While the above described arrangement o filaments,

conductors'and switch contacts is the one preferred, it

is obvious that modifications may be readily made. It.

is also obviousthat other' modifications may be made Without departure from the, scope of the invention.

Having'thus described my inventionwhat I claim "as new anddesire to'secure by Letters Patent isz-p l. An electric incandescent lamp-having` two laments 'and provided with three terminals, a base thereor coinprising a .screwlshell lfor engaging the lamp holder and forming one of the lamp terminals, an en insulating disk,

, a central terminal mountedon said disk nd a` third terminal mounted1on said disk between the center and periphery thereof, one vof said last mentioned terminals 'being resilient or yielding in axial-direction, said termi naisv being arranged out of line so that -e'acli may directly 'receive current fronithe lamp'holder independently of the other terminals. `r

2. An electric incandescent lamp having two filaments ,and provided with three terminals, a' base therefor comprising a screw-shell for engaging' the lamp holder and forming one of the lamp terminals, an end: insulating disk, 'a central terminal and a third annular, concentricterminal mounted on said disk, one or said last mentioned terminalsV being resilient or yieldingin axial direction said three terminals being arranged out of line so that each may directly engage its corresponding terminal of the lamp socket.

3. A n electric incandescent lamp having two filaments and provided with three terminals, a base therefor comprisln'ga screw-shell for engaging the lamp holder and forming one of the lamp terminals, an end insulating disk, a central terminal mounted on said disk and a third l annular, axially yielding terminal concentrica'lly mounted aillent -or yielding in axial direction, three conductors connected totheterminais of said lamp holder and yextending therefrom to a distant point and a switch are ranged to connect and disconnect said conductors and the lmain -supply wires and to modify. the flow of current through said conductors and filaments.'

v5fIn electric lighting,l the combination with an electric incandescentlamp having two laments and with a holder therefor, said lamp and holder having three pairs of co-operatlng terminals, each pair arranged to transmit current from the holder' to the lamp independently of the other pairs of terminals interengaging'screw-shells von said lamp -and holder forming one pair of terminals, insulating portions connectedto said screw-shells, a pair'of c'o-operating central terminals mounted on said insulating portions and a third pair of 'terminals mounted on saidinsulating .portions between said central and said screwshell' terminals, one of said pair of intermediate lterminais being resilient or .yielding in axial direction, three.

conductorsconnected to the terminals of said lamp holder and extending therefrom to a distant point and a switch arranged to connect and disconnect said conductors and the inain supply wires and-to modify the iiow ofi-current through said conductors and filaments.

6. In electric lighting, the combinato/n'with an electricincandescent lamp having two filaments and with` a` holder therefor, said lamp and holder having three pairs of co-operating terminals, each pair arranged 'to transmit current from the holder to the lamp independently of the other pairs of terminals inter-engaging screw-shells on said lamp and holder forming one pair of terminals, insulating portions connected to said screw-shells, a -pair of cooperating central terminals mounted on said insulating portions and a'thirdpairof annular terminals/concentrically mounted upon saidA insulating portions, Vone ot' said annular terminals being resilient or yielding in axial direction. p

7. In constant potential electric lighting, the combination with an incandescent lamp having filaments differing in candle power and in resistance per unit oi? length, of a lamp holder therefor, said lamp and holder having three pairs of co-operating terminals each pair arranged. -to transmit current from the holder to the lamp lndepe`n-i dently of the other pairs of terminals, -one of which is resilient, three conductors connected respectively to the terminals of said lamp holder and extending therefrom to a distant point and a switch' arranged to connect and disconnect said` conductors and the main current supply wires and to modify the tlow of current through said conductors and filaments. 

